The two Hollywood stars headed to the English music event, which took place over the weekend, to get muddy in a field and enjoy the performances on offer.

According to British newspaper The Sun, the men were spotted at the Shangri-La area of Worthy Farm and stayed out until 4 in the morning.

“The boys were out to enjoy themselves big time," a source told the publication.

“After midnight on Saturday, they made their way to Shangri-La and then on to The Rabbit Hole. Revellers couldn’t believe their eyes as they were dancing and stayed for a couple of hours."

Bradley, 39, was spotted blending into the crowds as he watched rockers Metallica on stage. He was trying to be incognito, dressed down in a T-shirt and grey baseball cap.

Luckily the buzzing atmosphere at the festival meant many fans didn't even register that the Silver Linings Playbook star and 37-year-old Michael were among them.

“They kept moving when people realised who they were but it was pretty late," the insider continued.

“Most people were too drunk to care and didn’t hassle them too much.”

Bradley could have gotten a taste for the UK music scene thanks to his relationship with 22-year-old British model Suki Waterhouse. The young fashion star took to Twitter to warn festival goers to look after themselves.

"Please be careful festi goers!!!!!! :(Ketamine blamed after man, 26, dies at Glastonbury (sic)," she tweeted, adding a link to an article about the incident.

Other acts entertaining the crowds over the weekend included Dolly Parton and Arcade Fire.